In most conventional vehicle doors, lateral edges of the height-adjustable window pane are concealed in grooves of legs of a window frame. Because of manufacturing tolerances, minor deviation between the adjusting direction of the window pane and the longitudinal direction of the grooves can occur so that the gap between an edge of the window pane and the bottom of the groove receiving the edge can change during the course of the movement of the window pane. In a conventional door, such a deviation is no problem provided it does not become so large that the edge disengages from the groove or runs up against the bottom of the groove.
When however at least one of the lateral edges is not concealed in a groove but visible, it should then be ensured that at least in the closing position of the window, in which the lateral edge of the window pane is visible in maximum length, the gap between the edge and a surface of a leg located opposite can be minimized. Moreover, this gap should substantially be the same whenever the window is closed. It is desirable, furthermore, to achieve this minor, reproducible gap without increased requirements on the manufacturing tolerances of the components used in the vehicle door.